Mobile terminals or subscriber stations, by their very nature, need to determine what wireless communication networks are available to them and to which networks they may connect. i.e. Network Discovery and Selection (ND&S). For example, the WiMAX communication system (IEEE 802.16e) allows a base station to provide Network Service Provider (NSP) information to subscriber stations that it serves. This information can be sent in a specific communication (unicast) to particular subscriber stations, or can be sent in a general communication (periodic broadcast) to all available subscriber stations that the base station serves.
One problem in using unicast is that sending NSP information individually to each subscriber station (SS) requires separate messaging for each SS and is therefore wasteful of signaling air capacity. Another problem is that unicast may not be practical because of the NSP information size. For many base station configurations, the downlink frame size (which is dictated, for example, by channel bandwidth, frame ratio and coding rate) does not allow for large NSP information to be unicast because it is undesirable to use a large percentage of the frame for a single SS. However, one advantage of unicast is that latency will be minimal since a unicast may be sent immediately.
A problem with periodic broadcast is that these broadcasts occur infrequently which can result in unacceptable latency and poor user experience. This is because periodic broadcasts cannot be too frequent as it would be wasteful messaging when very few SSs are performing ND&S. For example, in the current WiMAX standard, the default for sending periodic broadcast of NSP information is every 10 seconds. Hence, the ND&S latency could be as much as ten seconds or more if only periodic broadcasting of NSP information is used. The present WiMAX standard allows for unicasts and/or periodic broadcasts, but the existing implementation of the WiMAX standard suffers from the above latency and signaling air traffic capacity problems.
What is needed is an apparatus and method that allows for a solution that provides a balance between reasonable latency and optimized use of signaling traffic capacity.
Skilled artisans will appreciate that common but well-understood elements that are useful or necessary in a commercially feasible embodiment are typically not depicted or described in order to facilitate a less obstructed view of these various embodiments of the present invention.